Electrical key support membrane

ABSTRACT

Keyboards and other input devices are provided with membranes that extend under the keycaps or buttons. The membranes are flexible and can support conductive structures, traces, and electrical switch connections to enable effective key switches, lighting, and fluid-tightness for the keyboard. The flexible membrane is positioned near the keycaps to prevent ingress of fluids and debris into the lower portions of the key assemblies. In some cases, the flexible membrane also provides support for an interstitial layer that extends between keycaps.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This is a continuation of U.S. patent application Ser. No. 16/426,681,filed 30 May 2019, and entitled “ELECTRICAL KEY SUPORT MEMBRANE,” whichclaims priority to U.S. Provisional Patent Application No. 62/733,549,filed 19 Sep. 2018, and entitled “ELECTRICAL KEY SUPPORT MEMBRANE,” thedisclosures of which are hereby incorporated by reference in theirentireties.

FIELD

The described embodiments relate generally to keyboards and inputdevices for computers and other electronic devices. More particularly,the present embodiments relate to flexible electrical structures used inkeyboards.

BACKGROUND

Electronic devices use a variety of different input devices. Examples ofsuch input devices include keyboards, computer mice, touch screens,buttons, trackpads, and so on. They may be incorporated into anelectronic device or can be used as peripheral devices. The electronicdevice may be vulnerable to contaminants, such as dust or liquid,entering though openings or connections in or around one or moreincorporated input devices or external input devices. The external inputdevices may themselves be vulnerable to contaminants entering throughvarious openings or connections. The device may also implement lightingat the user interface.

Keyboards typically involve a number of moving keys. Liquid ingressaround the keys into the keyboard can damage electronics. Residues fromsuch liquids, such as sugar, may corrode or block electrical contacts,prevent key movement by bonding moving parts, and so on. Solidcontaminants (such as dust, dirt, food crumbs, and the like) may lodgeunder keys, blocking electrical contacts, getting in the way of keymovement, and so on. These devices can be undesirably expensive to makeand assemble.

Thus, there are many challenges and areas for improvements in inputdevices.

SUMMARY

Aspects of the present disclosure relate to a keyboard having a housing,a controller connection to provide an electrical connection to akeyboard controller, a flexible membrane having a set of conductivestructures, with each conductive structure of the set of conductivestructures being electrically connected to the controller connection, aset of keycaps positioned on an outer side of the flexible membrane, anda set of keycap supports positioned on an inner side of the flexiblemembrane. The set of keycap supports can be supported by the housing.

In some embodiments, the flexible membrane can include a first layerportion having a first conductive structure of the set of conductivestructures, a second layer portion having a second conductive structureof the set of conductive structures, and a spacer vertically separatinga first conductive structure from the second conductive structure. Theflexible membrane can be deformable to bring the first conductivestructure into electrical communication with the second conductivestructure, and the first layer portion and the second layer portion canextend under multiple keycaps of the set of keycaps. The first layerportion can extend under multiple keycaps of the set of keycaps, and thesecond layer portion can extend under one of the multiple keycaps.

The flexible membrane can be fluid-tight, and can have a light sourceelectrically connected to a conductive structure of the set ofconductive structures. The flexible membrane can have a vent aperturepermitting air to be redistributed through or external to the membrane.The membrane can be substantially flat or can have a set of locallyraised portions corresponding to the positions of the keycaps of the setof keycaps.

Another aspect of the disclosure relates to a button for an electronicdevice. The button can include a button cap and an elastic support layerattached to the button cap. The elastic support layer can have a set ofconductive traces providing conductive paths across the elastic supportlayer. The button can also include a set of support structuressupporting the elastic support layer and the button cap, whereinapplication of a force to the elastic support layer deforms the elasticsupport layer and enables electrical communication between twoconductive paths in the set of conductive traces.

Application of the force can cause the two conductive paths to contacteach other. Application of the force can also cause a bridge conductorto electrically contact the two conductive paths. The bridge conductorcan be positioned on a collapsible dome. The set of support structurescan have a collapsible dome configured to deform upon application of theforce and a stabilizer configured to limit rotational movement of thebutton cap upon application of the force. The elastic support layer canhave a collapsible dome portion. A flexible layer can be included thatis positioned around a perimeter of the button cap, with the flexiblelayer being supported by the elastic support layer. The button cap canbe positioned on an upper side of the elastic support layer. The buttoncap can be positioned on an underside of the elastic support layer.

Yet another aspect of the disclosure relates to a keyboard that includesa housing having a rigid web portion, a first flexible support layerhaving a lower portion and a raised portion, with the raised portionbeing raised relative to the lower portion and with the lower portionbeing attached to the rigid web portion of the housing, a secondflexible support layer being attached to the raised portion of the firstflexible support layer and being vertically spaced above and positionedover the lower portion, and a keycap positioned above the raised portionof the first flexible support layer.

Application of a force to the keycap can cause the keycap to travel anddeform the first and second flexible layers without the travel beinglimited by the rigid web portion. The second flexible support layer caninclude a fabric material. A third flexible support layer and a keycapsupport can be included as well, wherein the third flexible supportlayer is positioned between the keycap support and the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 shows an isometric view of an electronic device according to anembodiment of the present disclosure.

FIG. 2 shows an isometric view of another electronic device according toan embodiment of the present disclosure.

FIG. 3 shows an exploded view of a key assembly shown at box 3 in FIG.1.

FIG. 4 is a non-exploded side section view of the key assembly of FIG.3, as indicated by section line 4-4.

FIG. 5 is an exploded view of a membrane according to an embodiment ofthe present disclosure.

FIG. 6 is a side section view of a key assembly incorporating themembrane of FIGS. 3 and 5.

FIG. 7 is an exploded view of a membrane according to an embodiment ofthe present disclosure.

FIG. 8 is a side section view of a key assembly having the membrane ofFIG. 7.

FIG. 9 is a side section view of a key assembly of another embodiment ofthe present disclosure.

FIG. 10 is a side section view of a key assembly of another embodimentof the present disclosure.

FIG. 11 is an isometric view of a keyboard assembly of the embodiment ofFIG. 10.

FIGS. 12-14 show side views of various membrane and keycap embodimentsof the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following descriptions are not intended to limit the embodiments toone preferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined by theappended claims.

The description that follows includes sample systems and apparatusesthat embody various elements of the present disclosure. However, itshould be understood that the described disclosure can be practiced in avariety of forms in addition to those described herein.

The present disclosure relates to keyboards and/or other input devicesthat include mechanisms that prevent and/or alleviate contaminantingress, provide electrical switches, reduce the thickness of and thenumber of parts in the key assembly, and provide and distribute lightthrough the keyboard. These mechanisms can include keyboard membranes orgaskets and structures such as pads, fabric sheets, skirts, elastomer orother bands.

Aspects of the disclosure relate to a membrane or other type of flexiblelayer to which keycaps or button caps are connected in a keyboard. Theflexible membrane can limit or prevent ingress of fluids or debris toparts of the keyboard below the membrane. The membrane can be positionedbetween outer keycaps and inner portions of the keyboard such as innerkeycaps, collapsible domes, stabilizers (e.g., a butterfly or scissorhinge mechanism), and base components (e.g., a substrate, base layer,housing, etc.). Fluid and debris that falls between the keycaps can beblocked and held by the membrane at a location where it can be moreeasily cleaned off or otherwise removed from the keyboard. The fluid anddebris can also thereby be prevented from coming into contact withelectrically charged portions of the keyboard or interfering with thefunction of domes, stabilizers, and other moving parts of the keyboard.

The membrane can also include electrically conductive material to formconductive structures, conductive paths, or circuitry on the surface of,or within, the membrane. Portions of the membrane can be operated asdeformable switches that produce electrical signals in the mannertraditionally provided by switches and traces on a substrate (e.g., aprinted circuit board (PCB)). In some cases, domes or other deformablestructures are attached to the membrane and comprise conductive portionsthat are configured to contact and enable electrical communicationbetween portions of the conductive material of the membrane. Integratingthe conductive material into the membrane can reduce the number of partsin the keyboard and can relocate switch structures away from asubstrate.

The membrane can also include light sources and other light-distributingfeatures such as light-emitting diodes (LED) and reflective orlight-diffusive shapes and materials to provide lighting in and aroundthe keycaps connected to or otherwise associated with the membrane. Thelight-emitting components can have their electrical connectionsestablished by the conductive structures in the membrane. The membranecan distribute the light through its thickness, through domes connectedto the membrane, or with another diffuser or reflector attached to themembrane. Thus, the membrane can allow the keyboard to have its lightsources positioned nearer to keycaps to improve their efficiency and tohelp direct the light to where it is most beneficial.

In some configurations, the membrane includes internal voids from whichair can be redistributed throughout the membrane (or redistributed outof the membrane) when the membrane deforms. Thus, the membrane can beused to support or provide a variety of keyboard functions.

Additional embodiments, features, and details will be provided withreference to the figures. FIG. 1 depicts an electronic device 100including a keyboard 102. The keyboard 102 includes keys or keyassemblies with keycaps 103 or button caps that move when depressed by auser. The electronic device 100 can include one or more mechanisms thatprevent or alleviate contaminant ingress into or through the keyboard102, such as ingress between the keycaps 103 and into a housing 104 ofthe electronic device 100. Such mechanisms can include a flexiblemembrane extending across or underneath the keycaps 103. Suchcontaminants can include liquids (e.g., water, soft drinks, sweat, andthe like), solids (e.g., dust, dirt, skin particles, food particles, andthe like), and any other small debris or foreign material.

FIG. 2 illustrates a tablet computer 200 connected to a keyboard 202.The keyboard 202 is a peripheral device connected to the tablet computer200 rather than being an integral part of the tablet computer 200. Thekeyboard 202 can also include keycaps 203 and a housing 204 that areseparate from, but attachable to, the tablet computer 200. As explainedbelow, the keycaps 203 can be positioned on top of (or, in someembodiments, underneath) a flexible membrane.

Although the electronic device 100 of FIG. 1 is a notebook/laptopcomputer and a tablet computer 200 is shown in FIG. 2, it will bereadily apparent that features and aspects of the present disclosurethat are described in connection with the notebook computer and tabletcomputer 200 can be applied in various other devices. These otherdevices can include, but are not limited to, personal computers(including, for example, computer “towers,” “all-in-one” computers,computer workstations, and related devices) and related accessories,speakers, graphics tablets and graphical input pens/styluses, watches,headsets, other wearable devices, and related accessories, vehicles andrelated accessories, network equipment, servers, screens, displays, andmonitors, photography and videography equipment and related accessories,printers, scanners, media player devices and related accessories,remotes, headphones, earphones, device chargers, computer mice,trackballs, and touchpads, point-of-sale equipment, cases, mounts, andstands for electronic devices, controllers for games, remote control(RC) vehicles/drones, augmented reality (AR) devices, virtual reality(VR) devices, home automation equipment, and any other electronic devicethat uses, sends, or receives human input. Thus, the present disclosureprovides illustrative and non-limiting examples of the kinds of devicesthat can implement and apply aspects of the present disclosure.

The keyboard 102 can include a set of assembled components thatcorrespond to each key. The assembly of these components can be referredto as a “stack-up” due to their substantially layered configuration.FIG. 3 illustrates partial exploded view of an assembly 300corresponding to one of the keys in keyboard 102, as indicated by box 3in FIG. 1. One or more assemblies 300 can be implemented in the keyboard102, such as one for each keycap 103 or button. Some of the parts of theassembly 300 can span multiple keys or can extend beyond the limitsshown in FIG. 3 in one or more directions, as indicated by jagged edgelines. For example, as explained herein, the base layer 304 and membrane306 can extend across the underside of all of the keys in the keyboard102. FIG. 4 shows a simplified section view of the keyboard assembly 300in an assembled condition, as indicated by section line 4-4 in FIG. 3.Some parts are not shown in FIG. 4 in order to provide clarity regardingthe relationship between other parts.

As shown in FIGS. 3-4, a keyboard assembly 300 can include a keycap 103,a first flexible support layer (i.e., an interstitial layer 302)positioned at least partially under and around the base of the keycap103, a second flexible support layer (i.e., a flexible membrane 306,which may also be referred to as an elastic support layer) positionedunder the interstitial layer 302, a hinge mechanism (i.e., keystabilizer 308), a collapsible dome 310, a dome support 312, an adhesivelayer 314, a stiffening structure (e.g., a web 316), and a base layer304.

The keycap 103 can provide a surface against which the user caninterface with the keyboard assembly 300. Thus, the keycap 103 can bemovable between an unactuated state at a first vertical positionrelative to the base layer 304 and an actuated state at a secondvertical position relative to the base layer 304. The keycap 103 cancomprise a rigid material such as a hard plastic, metal, or ceramicmaterial. In an example embodiment, the keycap 103 includes a glass orpolymer. The keycap 103 can therefore include a glyph or symbol (notshown) on its surface. In some cases, the keycap 103 can be at leastpartially transparent or translucent, thus allowing light to betransferred through the keycap 103. The light can be directed through oraround a glyph or symbol of the keycap 103 in order to improve itscontrast and readability. In some embodiments, light is directed throughor around an outer perimeter of the keycap 103. The keycap 103 can bepositioned on an outer side (e.g., a top side) of the flexible membrane306 or can be positioned on an inner side thereof (e.g., a bottom side).In some configurations, the keycap 103 can be embedded in the flexiblemembrane 306. For example, the flexible membrane 306 material can beovermolded to the top of the keycap 103. An overmolded membrane 306 canprovide a seal around multiple sides of the keycap 103 and can helpprevent the keycap 103 from being dislodged from the membrane 306 orbeing damaged. In other embodiments, the keycap 103 can be attached tothe flexible membrane 306 by an adhesive material such as a glue,adhesive, or tape. In various cases, the keycap 103 can have a flat topsurface or a dished or cylindrical “scooped” top surface.

In some embodiments, a keycap 103 is on the outer side of the flexiblemembrane 306 and a second keycap is positioned on the inner sidethereof. The outer keycap can provide key feel/definition and the visualappearance of the key for the user, and the inner keycap can beconfigured to connect to the key stabilizer 308, dome 310, and any othercomponents below the flexible membrane 306. The keycap 103 canalternatively comprise a connection to the key stabilizer 308 throughthe flexible membrane 306 without use of a second or inner keycap.

The interstitial layer 302 can extend between adjacent keycaps 103 andcan span the gaps (i.e., interstices) between the keycaps 103. See FIG.4. The interstitial layer 302 can comprise a flexible material such asfabric, rubber, silicone, flexible polymer (e.g., thermoplasticpolyurethane (TPU)), HYTREL(R), related materials, or combinationsthereof. The interstitial layer 302 can therefore be referred to as afabric layer or a first flexible layer. The material used in theinterstitial layer 302 can be configured to be deflectable uponapplication of a force to a keycap 103 with which it is connected oragainst which it rests. Thus, the interstitial layer 302 can at leastlocally move along with a keycap 103 in a downward direction (e.g.,toward web 316) when a vertically oriented force is applied to thekeycap 103. The interstitial layer 302 can be configured to be flexibleenough that pressing one keycap 103 does not cause other nearby keycapsto significantly move as a result of the movement of the interstitiallayer 302. However, the interstitial layer 302 can also be rigid enoughthat it does not sag between the keycaps when they are in an unactuatedstate.

In some embodiments, the interstitial layer 302 is attached to thekeycap 103. The keycap 103 can be mounted to a top or inside surface ofthe interstitial layer 302 or the keycap 103 can be integrally formedwith the interstitial layer 302. For example, the keycap 103 can beadhered, co-molded, or overmolded with the interstitial layer 302. Thus,the keycaps 103 and interstitial layer 302 can form a single layer orsheet extending across the keyboard. In other embodiments, theinterstitial layer 302 is not attached to the keycap 103 or is omitted.If the interstitial layer 302 is not attached to the keycap 103, it canbe supported from below by the flexible membrane 306 to help positionthe interstitial layer 302 in contact with the underside of the keycaps103, even while the keycaps 103 move.

The flexible membrane 306 extends under the keycap 103 and interstitiallayer 302. The flexible membrane 306 can be flexible and deflectable inresponse to application of a downward force on the keycap 103. Thus, thekeycap 103 can contact the top of the flexible membrane 306 and deformpart of the membrane 306 when a sufficient force is applied to thekeycap 103. The flexible membrane 306 can comprise a thin, flexiblematerial such as HYTREL(R) from DUPONT™, thermoplastic polyurethane(TPU), rubbers, polyethylene terephthalate (PET), other thermoplasticmaterials, related flexible materials, and combinations thereof. In someembodiments, the flexible membrane 306 can comprise multiple materials,wherein portions of the flexible membrane 306 that are localizeddirectly underneath hard keycaps 103 can comprise a relatively rigidmaterial (e.g., PET), and portions between keycaps 103 (e.g., adjacentto lower portion 326) can comprise a relatively more flexible material(e.g., PET with reduced thickness, TPU, or a similar material). Using amore rigid material under the keycaps 103 can reduce the effects offatigue caused by contact between the dome and the under-key portions ofthe flexible membrane 306.

The membrane 306 can provide a fluid-tight barrier between an outerside/upper side 318 of the membrane 306 (i.e., the top side shown inFIG. 3 facing toward the keycap 103) and an inner side/lower sidethereof (i.e., the bottom side facing toward the base layer 304 oppositethe outer side 318). The fluid-tight barrier can prevent ingress of air,water, and other fluids from the outer side 318 to the inner side. Insome embodiments, the membrane 306 can be fluid-tight across the entirekeyboard, such as being fluid-tight across the entire width of themembrane 306 or across the entire width that is located under the widthof the keycaps. Specifically, the outer side 318 of the membrane 306 canbe fluid-tight. The inner side can potentially include openings orvents, as explained below.

The flexible membrane 306 can support the interstitial layer 302 andkeycap 103. Thus, when the keycap 103 and the interstitial layer 302move downward along the central axis 322 (see FIG. 4), the flexiblemembrane 306 can keep the interstitial layer 302 in contact with thebottom of the keycap 103. The flexible membrane 306 can thereforeinclude a raised portion 324 that is positioned vertically higher than alower portion 326, and the raised portion 324 can deflect downward asthe keycap 103 moves. The lower portion 326 can be positioned on the web316 and can be attached to the web 316 to limit upward movement of theflexible membrane 306. The flexible membrane 306 can be configured to beflexible enough to provide very little resistance to the movement of thekeycap 103.

The flexible membrane 306 can comprise conductive structures (e.g.,conductive traces or wires) that extend through the flexible membrane306 to the locations of each keycap 103. The conductive structures cancomprise an electrically conductive material, such as, for example,silver, copper, aluminum, other conductors, and combinations thereof.The conductive structures are described in greater detail in connectionwith FIGS. 5-9 below.

The flexible membrane 306 can have conductive structures connected to alight source 320 positioned on or in the membrane 306. The light source320 can be a light-emitting diode (LED) or related electronic deviceconfigured to output light in response to an electrical signal. Thus,the conductive structures on or in the membrane 306 can provide power tothe light source 320. The light source 320 can be a directional lightsource such as, for example, a directional LED configured to emit lightprimarily in one direction or through a limited range of angles relativeto a central axis extending through the light source 320. In variousembodiments, the light source 320 can emit light laterally into a sidesurface of the membrane 306 (e.g., into the lateral side of puck 504;see FIGS. 4 and 6), laterally into the collapsible dome 310, verticallyinto a bottom surface of the membrane 306 (see, e.g., light source 1020of FIG. 10), or at an angle toward the center of the keycap 103.

As shown in FIG. 4, the light source 320 can be positioned radiallyoutward from the dome 310 relative to the central axis 322 and cantherefore shine its light in a radially inward direction relative to thecentral axis 322. In another embodiment, the light can be directedprimarily parallel to the central axis 322. The light source 320 can bepositioned under the keycap 103 and can, in conjunction with themembrane 306 and any other structures into which the light shines,illuminate the bottom and/or perimeter of the keycap 103, therebyimproving the visibility of the outer limits of the keycap 103 orimproving the visibility of a translucent glyph- or symbol-formingportion of the keycap 103, especially in low-light environments. Thesurfaces of the membrane 306, dome 310, and any other nearby componentscan be configured to reflect or diffuse light in a desired direction(e.g., upward) or toward a border, glyph, or symbol of the keycap 103.

Because the light source 320 is positioned on the flexible membrane 306,the light source 320 can move with the flexible membrane 306, therebyimproving the consistency of the brightness of the light emitted throughor around the keycap 103 as compared to conventional lighting that ispositioned at or near the base layer 304. The distance between the keyglyph/key symbol/perimeter of the keycap 103 and the light source 320can be consistent irrespective of the position of the keycap 103relative to the base layer 304. Additionally, because the light source320 is located very close to the keycap 103, the light can be morefocused on its intended target (e.g., through the glyph) instead ofhaving to be reflected or diffused through material to reach the target.Thus, the light source 320 can appear brighter or can be a lessenergy-consuming source of light than conventional keycap light sources.

The key stabilizer 308 can comprise mechanical hinge or relatedmechanism configured to stabilize the movement of the keycap 103 as itvertically travels through a movement cycle. The stabilization can limitor prevent the keycap 103 from rotating when an off-center-orientedvertical force is applied to the top of the keycap 103 (e.g., a forceapplied laterally offset from, but parallel to, center axis 322). Insome embodiments, the key stabilizer 308 keeps the keycap 103substantially parallel to the base layer 304 or another horizontal planewhen the keycap 103 is also oriented horizontally in its unactuated orneutral state. Thus, the key stabilizer 308 can include a scissormechanism, butterfly mechanism, or related device used to stabilize keysin keyboards. The key stabilizer 308 can comprise a rigid material andcan be optically translucent or transparent to help distribute lightthroughout the underside of the keycap 103.

The key stabilizer 308 can include features configured to attach to thekeycap 103. For example, the keycap 103 can have structures (e.g., hooksand clamping features, not shown) configured to clip or lock ontocorresponding structures (not shown) on the key stabilizer 308. Thestructures connecting the key stabilizer 308 and the keycap 103 canextend through the flexible membrane 306 if the keycap 103 is positionedon the upper side of the membrane 306. Any openings through the flexiblemembrane 306 that facilitate that connection can be sealed andfluid-tight. In some configurations, such as when the keycap 103 or aninner keycap is positioned under the membrane 306, these connectingstructures do not extend through the membrane 306.

The collapsible dome 310 can provide resistance and tactile feedback tothe user when the keycap 103 is pressed. The collapsible dome 310 canalso be used to bias the keycap 103 vertically upward when the keycap103 has been at least partially depressed. Thus, the collapsible dome310 can comprise a compressible or collapsible material configured toresiliently change shape upon application of a force to the dome 310.The material can comprise rubber, silicone, another related flexiblematerial, and combinations thereof.

In some embodiments, the collapsible dome 310 can include a conductivematerial configured to permit electrical current to flow through thedome 310. See, e.g., FIG. 9 and its related descriptions herein. Thecollapsible dome 310 can have a top surface contacting or attached tothe membrane 306 and a bottom surface contacting or attached to the baselayer 304.

The dome support 312 can provide a structure within which the dome 310is positioned. The dome support 312 can be positioned above the baselayer 304 and can substantially surround the dome 310. In someembodiments, the dome support 312 is affixed or coupled directly to themembrane 306 or base layer 304. An adhesive layer 314 can be positionedbetween the dome support 312 and the structure(s) to which it isattached. The dome support 312 can be located within the key stabilizer308 and can include features for coupling to the key stabilizer 308. Forexample, a butterfly mechanism key stabilizer can be pivotally coupledto the dome support 312 along the central pivot axes of the butterflymechanism. The dome support 312 can comprise a rigid material and can beoptically translucent or transparent to help distribute light underneaththe keycap 103. In some embodiments, the dome support 312 is omittedand/or the key stabilizer 308 can be pivotally connected to connectivestructures formed in or directly coupled to the base layer 304.

The web 316 is a rigid structure positioned below the keycap 103 andflexible membrane 306. The web 316 can be a separate part attached tothe base layer 304 or can be integrally formed with the base layer 304(e.g., a molded part of the base layer 304 or a shape formed in a milledbase layer 304). The web 316 can provide structural stiffness to thebase layer 304 and can be a structure that other components are mountedto, such as the flexible membrane 306. The web 316 can be configuredwith a height so that its top surface is positioned below the verticalposition of the bottom of the keycap 103 when the keycap 103 is at itsmost actuated/deflected position relative to the base layer 304. In thismanner, the web 316 does not come into contact with the keycap 103 evenwhen the keycap 103 is completely pressed. As such, the web 316 does notlimit the movement of the keycap 103 or cause the keycap 103 to have ahard and limiting “bottom-out” against the web 316. The maximumdeflection position of the keycap 103 can be above the top surface ofthe web 316. When using the keycap 103 normally, the user may not feelthe rigid web 316, even when the user's finger presses down between twokeycaps 103. Accordingly, this arrangement can help limit the hard,jarring feeling of a user's finger hitting a rigid, unyielding surfacewhile typing.

Some conventional keyboards have a rigid web between each keycap, so theweb needs to be positioned well below the tops of the keycaps to preventthe user from hitting the web when their finger hits a keycap near itsedge. However, this can leave open space between the top edges of thekeycaps, so debris and material can fall between, and potentially under,the keycaps. The embodiments of the present disclosure provide aninterstitial layer 302 and/or membrane 306 that are near the top surfaceof the keycap 103 and that can block or limit debris and fluids frompenetrating between adjacent keycaps 103. The interstitial layer 302 andmembrane 306 can be compliant when pressed by a finger, so the problemof having rigid structures between the keycaps 103 and near the top ofthe keycaps 103 can be alleviated or avoided.

The base layer 304 can be a housing or other rigid base structure of thekeyboard assembly 300. The base layer 304 can also comprise a substratesuch as, for example, a printed circuit board (PCB) having conductivetraces and other electrical components. In some embodiments, the lightsource 320 is positioned on the base layer 304 and light from the lightsource is directed up into the membrane 306 and redistributed laterallythrough the membrane into and around the keycap 103. In someembodiments, the base layer 304 includes brackets for retaining a keystabilizer 308 to the base layer 304.

FIGS. 5 and 6 illustrate additional detail about the embodiment of theflexible membrane 306 shown in FIGS. 3-4. FIG. 5 is a partially explodedview of the flexible membrane 306, and FIG. 6 is a schematic sectionview taken from Box 6 in FIG. 4. FIGS. 5 and 6 are not to scale and donot show all parts in order to provide greater clarity.

The flexible membrane 306 can comprise a first layer 500 and a secondlayer 502. The second layer 502 can comprise a set of flexible discs orpucks 504 configured to be individually attached to the bottom surfaceof the first layer 500.

The first layer 500 can comprise a set of conductive structures 506, andthe pucks 504 each comprise one or more conductive structures 508. Thesecond layer 502 can alternatively include a sheet of material laterallyinterconnecting the pucks 504 to each other without covering theconductive structures 508, 522 in the pucks 504. The conductivestructures 506 of the first layer 500 are in electrical communicationwith a controller connection 510 which provides an electrical connectionto a controller (e.g., a processor or keyboard controller configured toreceive switch signals and/or to send keycodes to a computer or otherelectronic device).

The first layer 500 can comprise a flexible, unitary, fluid-tightmaterial to provide the fluid-tightness described in connection withFIGS. 3-4. The conductive structures 506 can be positioned on a surfaceof, or extend within or through, the first layer 500 to providecontinuous conductive traces or leads, similar to traces in a PCB. Asshown in FIG. 6, the conductive structure 506 is located on the bottomsurface of the first layer 500 in this embodiment. In some embodiments,the first layer 500 can have a thickness between about 25 microns andabout 200 microns, and in some cases the first layer 500 can have athickness of about 50 microns. The conductive structures 506 can beflexible so that flexure of the first layer 500 does not break ordisable electrical communication through the conductive structures 506.

The first layer 500 can comprise a set of attachment points 512 on itsbottom surface where the pucks 504 of the second layer 502 are attached.Each attachment point 512 can have its own unique conductive structure506, or, as shown in FIG. 5, a single conductive structure 506 can passthrough or over multiple attachment points 512. Each puck 504 can beattached to a unique attachment point 512 at the upper surface of thepuck 504, such as at the upper surface of the puck 504 and around thetop perimeter of the puck 504. Each attachment point 512 can correspondto the location of a key in the keyboard. Thus, the attachment points512 can be distributed in a keyboard layout across the first layer 500.The conductive structure 506 through each attachment point 512 can beconfigured to align with the conductive structures 508 in the pucks 504.

The pucks 504 can comprise a cup-like shape wherein a horizontal lowermembrane 514 is connected to a hollow, vertical, cylindrical spacer 516.The lower membrane 514 and spacer 516 can be separate parts or can beformed integrally as a single piece. Similarly, the pucks 504 can eachbe a separate piece from the first layer 500 or can be an integral partof the first layer 500. The pucks 504 and first layer 500 can comprisePET or a similar material with low compressibility and high resistanceto the effects of compression fatigue.

The pucks 504 can comprise a flexible material similar to, or the sameas, the first layer 500. In some embodiments, the lower membrane 514 canhave a thickness between about 25 microns and about 200 microns, and insome cases the lower membrane 514 can have a thickness of about 50microns. In some embodiments, the spacer 516 can have a thicknessbetween about 75 microns and about 150 microns, and in some cases thespacer 516 can have a thickness of about 75 microns. The spacer 516 cancomprise a flexible material such as a pressure-sensitive adhesive(PSA), a thermoplastic polymer (e.g., polyethylene terephthalate (PET)),related material, and combinations thereof.

When the puck 504 is attached to the first layer 500, an internal void518 can be formed. See FIG. 6. The void 518 is between the conductivestructure 506 on the first layer 500 and the conductive structure 508 onthe lower membrane 514. The void 518 can provide a non-conductive airgap between the conductive structures 506, 508 so that there is noelectrical communication between the conductive structures 506, 508 whenthey are in the unactuated or neutral condition shown in FIG. 6.

When a downward force is applied to the keycap 103, pressure is appliedto the flexible membrane 306 that causes the membrane 306 to deform. Thepressure can come from a combination of the downward movement of theentire membrane 306 (as the keycap moves 103) and localized pressureagainst the lower membrane 514 of the puck 504. The localized pressurecan be applied by a portion of the dome 310 (e.g., localized arounddirectional arrow 520 in FIG. 6 upon collapse or deformation of the dome310). This pressure against the lower membrane 514 can urge theconductive structures 506, 508 together, thereby producing an electricalpath through a first conductive structure 506 of the first layer 500 andinto the conductive structure 508. The conductive structure 508 iselectrically connected to another conductive structure 522 in the spacer516 that is connected to another conductive structure 506 of the firstlayer 500. Thus, conductive structures in the flexible membrane 306 canform a collapsible switch that is actuated upon application of adownward force on the keycap 103. All of the electrical connections forthe switch can be located within the membrane 306 and can extend justbelow the keycap 103 and above the set of support structures below themembrane 306 (e.g., the key stabilizer 308, dome 310, and dome support312).

In some embodiments (not shown), the dome 310 can be integrally formedwith the puck 504. Thus, portions of the dome can deform to engage otherportions of the dome (e.g., portions corresponding to the lower membrane514) that bear conductive structures (e.g., 508).

The puck 504 can have a lateral width less than the width W of thekeycap 103, as shown in FIG. 4. In some embodiments, the puck 504comprises a lateral width about equal to or greater than the lateralwidth W of the keycap 103. This configuration can be beneficial when thepuck 504 is used to distribute light under the keycap 103 since the puck504 can therefore help distribute light around the perimeter of thekeycap 103 more effectively.

FIGS. 7 and 8 illustrate another embodiment of a flexible membrane 700that can be used in the keyboard assembly 300. FIG. 7 shows an explodedview of a portion of the membrane 700, and FIG. 8 shows a section viewcomparable to FIG. 6. The flexible membrane 700 can comprise a firstlayer 702 and a second layer 704. Each of these layers 702, 704 can havea construction and material makeup comparable to the first layer 500,wherein they comprise sets of conductive structures 706, 708. Theflexible membrane 700 can also include a spacer layer 710 positionedbetween the first and second layers 702, 704. The spacer layer 710 caninclude a set of openings or apertures 712 corresponding to the positionof each key in a keyboard. Thus, the apertures 712 can be distributed ina keyboard layout across the flexible membrane 700. Each of the firstand second layers 702, 704 can have corresponding attachment areas 714,716 where the apertures 712 of the spacer layer 710 are located.

The flexible membrane 700 can have the first layer 702 attached to(e.g., adhered or bonded to) the spacer layer 710, and the spacer layer710 can be attached to the second layer 704. Accordingly, due to thepresence of the apertures 712, a set of voids 718 can be formed withinthe membrane 700, between the first layer 702 and the second layer 704,comparable to the voids 518 of membrane 306. See FIG. 8. The conductivestructures 706, 708 can be configured to vertically cross-over eachother where they are spaced apart by the voids 718.

The voids 718 can lie between the conductive structures 706, 708 wherethe keycaps 103 are located, and the voids 718 can be collapsed bydeflection of the first and second layers 702, 704 toward each other.For example, the a portion of the dome 310 can be displaced relative tothe flexible membrane 700 such that it applies localized pressure tosecond layer 704 in direction 720, as indicated in FIG. 8, to causecontact and electrical communication between the conductive structures706, 708 within the void 718. In some embodiments, a conductivestructure 706 of the first layer 702 can be electrically connected to aconductive structure 708 of the second layer 704 by a bridgingconductive structure 722 extending through the spacer layer 710.

In some embodiments, the dome 310 can be integrally formed with thesecond layer 704. Thus, the second layer 704 can include collapsibledomes rather than the domes 310 being attached to the bottom surface ofthe second layer 704.

A flexible membrane 700 having multiple layers (i.e., 702, 704, 710) canbe beneficial due to providing multiple layers on which the conductivestructures 706, 708 can be positioned. The conductive structures 706 onthe first layer 702 can extend across the same vertical positions as theconductive structures 708 on the second layer 704, so the number ofjumpers, bridges, or similar structures in the membrane 700 can bereduced or eliminated. All of the conductive structures 706, 708 can bein electrical communication with a controller connection. Additionally,the conductive structures 706, 708 (and 506) can include diodes,resistors, and related electrical components commonly found in keyboards(not shown) in order to assist in uniquely identifying each key pressdifferently at the controller or to limit back-fed signals through theflexible membrane.

In some embodiments, the membrane 700 can comprise a single layercombining the three above-indicated layers 702, 704, 710 into one. Forexample, the first and second layers 702, 704 and the spacer layer 710can all be an integral part of each other and a single piece of materialrather than being multiple layers attached to each other. For example,the membrane can comprise the single layer, and voids (similar to 718)can be formed within the thickness of the single layer between locationswhere traces (e.g., 706, 708) can intersect or contact upon collapse ofthe voids. In another example, the spacer layer 710 and second layer 704can be omitted, and the conductive structures 706 can extend across on asingle membrane 702 with a set of jumpers and insulating spacers thatcan separate the conductive structures 706 similar to how the voids 718separate conductive structures 706, 708. The insulating spacers can holdan air gap between the conductive structures 706 that can be closed whena force is applied to the membrane 700 at the spacers. These insulatingspacers can be configured to withstand stretching. In someconfigurations, the insulating spacers are resilient and do not break orlose their electrical insulating properties upon being deformed in aswitch press event.

FIG. 9 illustrates a section view of another embodiment of a flexiblemembrane 900. In this case, the membrane 900 comprises a single layer902 having conductive structures 904, 906 separated from each other by agap 908 on the layer 902. A dome 910 is attached to the membrane 900 andcomprises a conductive portion 912. In this embodiment, when the key isdepressed at the dome 910, the dome 910 collapses resulting in relativedisplacement of the conductive portion 912 toward the conductivestructures 904, 906 in direction 920. Upon sufficient deflection, theconductive portion 912 engages both conductive structures 904, 906 andthereby permits electrical communication between the conductivestructures 904, 906. Accordingly, the conductive portion 912 can close acircuit with the conductive structures 904, 906 and enable an electricalsignal using the conductive structures 904, 906. The flexible membrane900 can be simpler and less costly to construct than other membranesbecause it only requires a single layer 902 of material and a set ofdomes 910.

In various embodiments disclosed herein, the flexible membrane (e.g.,membranes 306, 700, and 900) can comprise internal voids (e.g., voids518, 718, and 918). When the membranes are deformed, air in the voidscan be compressed due to the change in shape of the voids. Thecompression can provide resistance to the deformation of the membranes.

In some embodiments, the voids 518, 718, and 918 are vented so that aircan escape with little or no hindrance to the deformation. Thus, exampleventing features are shown in FIGS. 6, 8, and 9, wherein a bottom orside vent opening 530, 532, 730, 732, 930 can allow air to escape theinternal void through the bottom or side wall of the membrane or domethat forms a boundary for the internal void. Each internal void cancomprise one or more of the vent openings shown in these figures or ventopenings configured to serve a similar function.

The bottom and side vent openings 530, 532, 730, 732, 930 can bereferred to as exit openings or atmosphere exit openings since they canbe configured to vent air to the atmosphere external to and surroundingthe keyboard assembly. Accordingly, air pushed out through an exitopening or atmosphere exit opening can be replaced by substantiallydifferent air when the membrane elastically returns to its unactuated orundeformed state and draws in air from atmosphere through the exitopening. The air in the internal voids is part of a system open toatmosphere external to the membrane/domes instead of being part of aclosed pneumatic system. In some arrangements, the exit opening oratmosphere exit is positioned through the bottom or side of the membranein order to preserve the fluid-tightness of the upper surface of themembrane.

In other embodiments, the vent opening 732 can be referred to as adistribution opening or closed distribution openings, wherein airexiting the internal void 718 is forced into other parts of the membraneor keyboard (e.g., to other internal voids in the membrane). The air inthis case can be contained in a closed pneumatic system wherein airforced out of the internal voids 718 is replaced by air from within thesame system. In some arrangements, the air can be pressed through anindirect or torturous path between different parts of the closed system.

In some embodiments, a hybrid system is implemented, wherein themembrane comprises a set of fluidly interconnected internal voids and atleast one exit opening or atmosphere exit opening. Thus, the system canbe designed with a mostly contained system of air that is still able tovent to atmosphere if needed. This can be advantageous when the membraneis moved between different atmospheric pressures so that the pressurewithin the membrane stays within predetermined limits. For example, thepressure in the voids can be maintained to avoid a low pressuresituation where the voids collapse and cause unwanted electrical contactbetween conductive parts of the flexible membrane.

Another aspect of the disclosure includes methods for manufacturingflexible membranes described herein. In one embodiment, a sheet offlexible material (e.g., the material used in the first layer 500 orlayers 702, 704, or 900) is provided. The material can be generally flatwith a single thickness. The material can be embossed into shapes (e.g.,the raised portions shown in FIGS. 4, 10, 11, 13, and 14). The embossedshapes can correspond to the various sizes and shapes of the keycaps 103used with the membrane or the positions of an interstitial layerrelative to a set of keycaps.

Next, conductive structures (e.g., structures 506, 706, 708) can beadded to the embossed membrane. For example, conductive traces (e.g.,silver traces) can be added to different parts of the membrane using aprinting process. For instance, a three-dimensional inkjet can be usedto add a matrix of conductive material to the outer surfaces of themembrane. The conductive structures can provide electrical communicationbetween each key and a keyboard controller. In some embodiments, thisprocess can be repeated for each layer in the membrane and then themembrane can be assembled. In other cases, the process can be performedafter all of the layers of the membrane have previously been attached toeach other.

In another embodiment, a flexible sheet of material (or a preassembledentire membrane) is provided, and the conductive structures can be addedwhile the material is generally flat and unshaped. For example, aninkjet or screen printing process can apply conductive material asconductive traces to the surfaces of the flexible membrane. The sheetcan then be re-shaped (e.g., embossed). The material used for theconductive structures can therefore be designed with flexibility orcapability of elongation and bending in order to ensure that theconductive structures are not broken when the membrane is embossed.

In still another embodiment, the sheet of material can bepre-impregnated or coated with conductive material in an embossed orun-embossed configuration. An acid etching process, laser-etchingprocess, or similar removal process can then be used to eliminateconductivity where it is not needed on the membrane, and the non-removedconductive structures can remain on the membrane afterward where theyare needed.

In yet another embodiment, a molding process can be used to create themembrane. Conductive material (e.g., a decoration or in-mold film havingconductive structures) can be applied to the inner surfaces of the mold.Afterward, the membrane material can be added to the mold so that theconductive structures are bonded to the membrane material when they aredemolded.

FIG. 10 illustrates a section view of an alternate embodiment of akeyboard assembly 1000 comparable to keyboard assembly 300. In thisembodiment, parts having similar numbers correspond to theircounterparts in FIGS. 3-4 and can have similar features. The assembly1000 can comprise a lower flexible membrane 1022 in addition to theupper flexible membrane 1006. The lower flexible membrane 1022 canextend across the keyboard assembly 1000 below the dome 1010 and upperflexible membrane 1006. The lower flexible membrane 1022 can beconfigured with raised portions 1024 that extend over the top of the web1016. Thus, the keyboard assembly 1000 can have the web 1016 directlyattached to the base layer 1004 without having to break continuity ofthe lower flexible membrane 1022 for the web 1016 to extend through it.

The upper and lower flexible membranes 1006, 1022 can each have sets ofelectrically conductive structures running through them, and each of theflexible membranes 1006, 1022 can be used for different purposes in thekeyboard assembly 1000. For instance, the upper flexible membrane 1006can be configured to provide support for the interstitial layer 1002(e.g., in the manner explained above in connection with interstitiallayer 302) and to support and provide electrical connections for a lightsource 1020 on the upper flexible membrane 1006. The lower flexiblemembrane 1022 can include its own conductive structures configured tofunction as switches upon collapse of the dome 1010, as described abovein connection with the flexible membrane embodiments of FIGS. 4-9.

Accordingly, different flexible membranes can provide differentsupporting and electrical functions in the keyboard assembly 1000. Theupper membrane 1006 can be optimized to provide lighting and support forthe interstitial layer 1002 since it is located closer to the keycap1003 and interstitial layer 1002, and the lower membrane 1022 can beoptimized to provide switches for the keyboard assembly 1000 since it iscloser to the base layer 1004 and can therefore be easier to connect toother electrical components in the lower section of the keyboardassembly 1000.

One or both of the flexible membranes 1006, 1022 can prevent fluidpenetration through the keyboard assembly 1000. Thus, in embodimentswhere both membranes 1006, 1022 prevent fluid penetration, each can actas a backup layer of protection for the keyboard when the other fails.Additionally, the separate membranes can be optimized in size andthickness for their individual functions. If just one of the membranes1006, 1022 supports lighting, its shape, thickness, and materialcomposition can be optimized to enhance the diffusion or reflection oflight from the light source 1020 to where it is desired. For example, itcan comprise a transparent material while the other membrane 1006, 1022,which does not serve a lighting distribution function, comprises anopaque material.

As shown in FIG. 11, at least one of the flexible membranes of thekeyboard assembly 1000 (in this case, the lower flexible membrane 1022)can be arranged in a set of strips or rows 1100, 1102, 1104 across thebase layer 1004 and the web 1016 of the keyboard. The rows 1100, 1102,1104 can alternatively be configured as columns.

Each of the rows 1100, 1102, 1104 can provide its own conductivestructures for the key assemblies it supports, and portions of themembrane 1022 are omitted between the rows 1100, 1102, 1104. Thisconfiguration can be beneficial when the base layer 1004 and web 1016need to be designed with increased stiffness because the membrane 1022does not extend over portions of the web 1016. Thus, those uncovered webportions (e.g., portions 1106) can be thickened relative tomembrane-covered portions of the web 1016 (e.g., portions 1108) sincethere does not need to be extra space between the interstitial layer1002 and the web portions 1106 for the membrane 1022.

FIGS. 12-14 illustrate multiple embodiments showing alternaterelationships between keycaps 103 and a flexible membranes 1200, 1300,1400. The flexible membranes 1200, 1300, 1400 can be one of the otherflexible membranes disclosed herein (e.g., membranes 306, 700, 900, and1006). Thus, each of these flexible membranes 1200, 1300, 1400 canprovide conductive structures, lighting, etc.

In FIG. 12, the flexible membrane 1200 comprises a flat top surface 1202in an unactuated or neutral state. The keycaps 103 are placed on theflat top surface 1202 with spaces (e.g., 1204) between each other. Thekeycaps 103 therefore have an offset height 1206 relative to the flattop surface 1202 that is substantially equal to the entire thickness ofthe keycap 103. This can provide excellent key definition for the usersince each keycap 103 is clearly spaced from its neighboring keys. Thisembodiment can also make the membrane 1200 easy to clean due to the widespaces 1204 between keycaps 103.

In FIG. 13, the flexible membrane 1300 comprises a set of recesses 1302in its top surface 1304 in which the keycaps 103 are located. In thisembodiment, the top surface 1304 of the membrane 1300 that lies betweenthe keycaps 103 is nearly the same height as the height of the keycap103 relative to the top surface of a recess 1302. The top surfaces ofthe keycaps 103 can still be slightly raised relative to the top surface1304 of the membrane 1300. This embodiment can provide a relativelysmooth travel surface of fingers sliding laterally across the topsurface 1304 and keycaps 103. Additionally, lighting can be directedclose to the perimeters of the top surfaces of the keycaps 103. Thisconfiguration can also provide additional space below the membrane 1300since the top surface 1304 is raised relative to the recesses 1302.

In FIG. 14, the flexible membrane 1400 can extend over the top surfacesof the keycaps 103. This embodiment can be used to protect the keycaps103 and to give the top surface of the keyboard a consistent materialappearance and finish. Additionally, the feel of the surface of thekeyboard can be more compliant and flexible since it is based on thematerial used in the flexible membrane 1400 rather than being based onthe material used in the keycaps 103.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not intended to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

What is claimed is:
 1. A button for an electronic device, comprising: abutton cap; an elastic support layer attached to and contacting thebutton cap, the elastic support layer having a set of conductive tracesproviding conductive paths across the elastic support layer; a set ofsupport structures supporting the elastic support layer and the buttoncap, the set of support structures including a hinge mechanismconfigured to limit rotational movement of the button cap relative to ahorizontal plane; wherein upon application of a force to the elasticsupport layer, the elastic support layer deforms to enable electricalcommunication between two conductive paths in the set of conductivetraces.
 2. The button of claim 1, wherein application of the forcecauses the two conductive paths of the set of conductive traces tocontact each other.
 3. The button of claim 1, wherein application of theforce causes a bridge conductor to electrically contact the twoconductive paths.
 4. The button of claim 3, wherein the bridge conductoris positioned on a collapsible dome.
 5. The button of claim 1, whereinthe set of support structures comprises a collapsible dome configured todeform upon application of the force.
 6. The button of claim 1, whereinthe elastic support layer comprises a collapsible dome portion.
 7. Thebutton of claim 1, further comprising a flexible layer positioned arounda perimeter of the button cap, the flexible layer being supported by theelastic support layer.
 8. The button of claim 1, wherein the button capis positioned on an upper side of the elastic support layer.
 9. Thebutton of claim 1, wherein the button cap is positioned on an undersideof the elastic support layer.
 10. A keyboard, comprising: a housinghaving a rigid web portion; a first flexible support layer having alower portion and a raised portion, the raised portion being raisedrelative to the lower portion, the lower portion being attached to therigid web portion of the housing; at least two keycaps positioned abovethe raised portion of the first flexible support layer; a secondflexible support layer defining a top surface of the keyboard betweenthe at least two keycaps, being in contact with a top surface of theraised portion of the first flexible support layer, and being verticallyspaced above and positioned over the lower portion of the first flexiblesupport layer.
 11. The keyboard of claim 10, wherein application of aforce to a keycap of the at least two keycaps causes the keycap totravel and deform the first and second flexible layers without thetravel being limited by the rigid web portion.
 12. The keyboard of claim10, wherein the second flexible support layer comprises a fabricmaterial.
 13. The keyboard of claim 10, further comprising a thirdflexible support layer and a keycap support, the third flexible supportlayer being positioned between the keycap support and the housing. 14.The keyboard of claim 10, further comprising a dome, wherein the rigidweb portion extends from a base layer, wherein the dome is positionedbetween the base layer and the first flexible support layer.
 15. Akeyboard, comprising: a base layer; a rigid web extending upward fromthe base layer; a flexible membrane having a first portion raisedrelative to a second portion; a set of keycaps, at least one keycap ofthe set of keycaps being positioned at least partially over the firstportion of the flexible membrane; an interstitial layer positioned overthe first portion of the flexible membrane and spaced above the rigidweb, the interstitial layer extending horizontally between the at leastone keycap and a second keycap of the set of keycaps.
 16. The keyboardof claim 15, wherein the interstitial layer is flat between the at leastone keycap and the second keycap.
 17. The keyboard of claim 15, furthercomprising a second flexible membrane having an upper portion positionedon the rigid web and a lower portion extending between the at least onekeycap and the base layer.
 18. The keyboard of claim 15, furthercomprising a second flexible membrane having a lower portion positionedon the second portion of the flexible membrane and an upper portionextending between the at least one keycap and the base layer.
 19. Thekeyboard of claim 15, further comprising a light source on the flexiblemembrane.
 20. The keyboard of claim 15, wherein the flexible membranecomprises a set of conductive structures configured to function as atleast one switch in response to movement of the at least one keycaprelative to the base layer.